/Engine/Source/Runtime/CoreUObject/Public/UObject/PackageTrailer.h
Loads a payload that is stored locally within the package trailer. Payloads stored externally (either referenced or virtualized) will not load.
The payload in the form of aFCompressedBuffer. If the payload does not exist in the trailer or is not stored locally in the trailer then theFCompressedBufferwill be null.
[FCompressedBuffer](API\Runtime\Core\Compression\FCompressedBuffer) LoadLocalPayload ( const [FIoHash](API\Runtime\Core\IO\FIoHash) & Id, [FArchive](API\Runtime\Core\Serialization\FArchive) & Ar ) const